CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Millions		Total		Common Stock, $0.001 Per Share Par Value	Capital In Excess of Par	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, par value (in dollars per share)		$ 0.001
Beginning balance at Dec. 31, 2018		$ 489.6			$ 512.3	$ 26.4	$ (49.2)	$ 0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss)/income		16.9				16.9
Stock compensation plans		1.2			1.2
Net hedging losses, net of income tax		(0.1)					(0.1)
Foreign currency translation adjustments		1.0					1.0
Ending balance at Mar. 31, 2019		508.6		$ 0.1	513.5	43.3	(48.3)	0.0
Beginning balance at Dec. 31, 2018		489.6			512.3	26.4	(49.2)	0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss)/income		50.4
Net hedging losses, net of income tax		1.5
Foreign currency translation adjustments	[1]	(1.9)
Ending balance at Sep. 30, 2019		543.6		0.1	517.0	76.8	(49.6)	(0.7)
Beginning balance at Mar. 31, 2019		508.6		0.1	513.5	43.3	(48.3)	0.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss)/income		15.5				15.5
Stock compensation plans		2.4			2.4
Net hedging losses, net of income tax		0.5					0.5
Purchases of treasury stock - deferred compensation plan		(0.7)						(0.7)
Foreign currency translation adjustments		(1.0)					(1.0)
Ending balance at Jun. 30, 2019		$ 525.3		0.1	515.9	58.8	(48.8)	(0.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, par value (in dollars per share)		$ 0.001
Net (loss)/income		$ 18.0				18.0
Stock compensation plans		1.1			1.1
Net hedging losses, net of income tax		1.1					1.1
Foreign currency translation adjustments		(1.9)	[1]				(1.9)
Ending balance at Sep. 30, 2019		$ 543.6		0.1	517.0	76.8	(49.6)	(0.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, par value (in dollars per share)		$ 0.001
Common stock, par value (in dollars per share)		$ 0.001
Beginning balance at Dec. 31, 2019		$ 544.0		0.1	516.4	76.6	(48.3)	(0.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss)/income		(1.9)				(1.9)
Stock compensation plans		1.2			1.2
Shares withheld for taxes - common stock issuances		(0.7)			(0.7)
Foreign currency translation adjustments		(1.8)					(1.8)
Ending balance at Mar. 31, 2020		540.8		0.1	516.9	74.7	(50.1)	(0.8)
Beginning balance at Dec. 31, 2019		544.0		0.1	516.4	76.6	(48.3)	(0.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss)/income		(13.9)
Net hedging losses, net of income tax		(0.2)
Foreign currency translation adjustments	[1]	1.4
Ending balance at Sep. 30, 2020		566.6		0.1	551.7	62.7	(47.1)	(0.8)
Beginning balance at Mar. 31, 2020		540.8		0.1	516.9	74.7	(50.1)	(0.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss)/income		(0.2)				(0.2)
Stock compensation plans		1.0			1.0
Net hedging losses, net of income tax		(0.2)					(0.2)
Foreign currency translation adjustments		0.2					0.2
2025 Notes - discount net of issuance fees and income tax		29.5			29.5
Exercise of stock options		0.1			0.1
Ending balance at Jun. 30, 2020		$ 571.2		0.1	547.5	74.5	(50.1)	(0.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, par value (in dollars per share)		$ 0.001
Net (loss)/income		$ (11.8)
Stock compensation plans		1.2			1.2
Net hedging losses, net of income tax		0.0
Foreign currency translation adjustments		3.0	[1]				3.0
2025 Notes - discount net of issuance fees and income tax		2.7			2.7
Exercise of stock options		0.3			0.3
Ending balance at Sep. 30, 2020		$ 566.6		$ 0.1	$ 551.7	$ 62.7	$ (47.1)	$ (0.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock, par value (in dollars per share)		$ 0.001

[1] Income taxes are not provided on the equity in undistributed earnings of our foreign subsidiaries because it is our intention that such earnings will remain invested in those subsidiaries indefinitely.